Converting to lithium...keep my converter (for now)?

[SolarPoweredRV]

I just watched this video [again] last night and around the 12 minute mark he shows his new converter pushing 14.5v and mentions [does not show] that the battery end is at 13.4v.

This is why a standard converter only charged his lithium batteries to 53%. He has a 1.1v voltage drop to his batteries. Assuming his standard converter tops out at the factory voltage of 13.6v, with a voltage drop of 1.1v, his charging voltage would be 12.5v. If I recall, my loss is around .1v@45-50A. I do understand if the charging current is lower, the voltage drop would be less.

I would think a TV repairman would notice that kind of drop and do something about it.

Two thoughts on this...

First, because the coach is using energy while still charging the batteries, there isn't really a 1.1 volt drop, there is probably a 0.5 volt drop with the remainder being consumed by the coach.

Second, in Ray's situation, his Converter is not his primary source for recharging his batteries. He relies on his Solar panels and if he needs to charge his batteries from his generator, he has a (80-95 amp) Progressive Dynamics Converter installed in his battery compartment that he uses instead of charging through the OEM Converter. This PD Converter is not a "Lithium Capable" Converter, however, it does have a "Desulfication" mode that brings the voltage up to 14.4v and he just manually turns that mode on if he needs to charge the Lithium batteries.

[Butcher]

He does show that the converter is pushing 55A and the batteries are taking in 45A. There is 10A going somewhere, which he does mention there are items turned on in the RV.

I like tests and the results of those tests. His video's give basic tests and I am only assuming that is what his target audience wants. I certainly turn the page if someone talks too high tech. The subject of the video was not to find out why his batteries would not charge above the 53% mark, but to show how to install an AD converter that could solve that problem.

I have a tough time assuming .6v drop is from the consumers. 80% of the load is going to the battery. 20% is going to the panel. Thinking that .6v is most likely from the consumers seems high. The power lead is much shorter, the current is only 10A on that lead, I just do not see it. Of course, none of those tests were done. It is a fact he mentions that his batteries were only at a 53% SOC and it appears that he blames the converter for that. Yes, it does contribute to it but I believe if he addressed the way the power gets to his batteries it yield a higher state of charge.

I'm no electrician and my thought are just that. It's what keeps my brain from spinning out of control. I do know, I have fixed a lot of electrical problems on some of the most expensive cars in the world because of voltage drops.

[deeuubee]

I just wanted to add my personal experience.

I have the original WFCO 8955 LA converter in my 21' - 25G and 540 Ah lithium batteries.
When I need them charged for a trip, I plug in my Progressive Dynamics 60 amp charger mounted in the storage compartment.

Just for S&G's I ran them run down to 28% (13.1V) when I got home to see what they would charge to.
It's been a week now on shore power with the only loads being the smoke and CO detectors.
13.23V @ 51%

When I plugged into shore power, it showed 15A, after 15 minutes, it was only 2 amps.
Now it shows 0.025 amps, so it seem that the LA converter sees the 13.23V as fully charged.

Maybe if I drained them down below 12V or so I might have gotten more amps, but it takes forever to drain those darn things

[sande005]

Well, as the OP - you all have given me great food for thought!
In my case, I was lucky enough to be able to contact the storage lot owner, who happened to be standing near my trailer. During the call, he stepped over, took the wrench I left there also, and disconnected the GC2's. So yea! I won't have killed batteries in Jan.
Now I can take a bit more time to ponder the matter - the boat still needs its AGM's replaced. It's a 24v system. 2 100Ah are way more than I need...but if they are to do future duty in the RV, then are the minimum replacements for the GC2's. And there is the charger in each vehicle to consider....decisions, decisions....

[ajg617]

I just wanted to add my personal experience.

I have the original WFCO 8955 LA converter in my 21' - 25G and 540 Ah lithium batteries.
When I need them charged for a trip, I plug in my Progressive Dynamics 60 amp charger mounted in the storage compartment.

Just for S&G's I ran them run down to 28% (13.1V) when I got home to see what they would charge to.
It's been a week now on shore power with the only loads being the smoke and CO detectors.
13.23V @ 51%

When I plugged into shore power, it showed 15A, after 15 minutes, it was only 2 amps.
Now it shows 0.025 amps, so it seem that the LA converter sees the 13.23V as fully charged.

Maybe if I drained them down below 12V or so I might have gotten more amps, but it takes forever to drain those darn things

I went 11 days without shore, solar, generator being able to get SOC above 71% after an evening discharge to 11.7V but a SOC of 43% - still trying to figure that out. 40 minute diagnostic phone call with Progressive Dynamics - disconnect shore and solar and run the batteries down below 12.8V by turning on the fans and/or furnace. Then turn off fans and turn shore power back on (I did that at the breakers inside). Seems the PD 9160ALV can get fooled with a heavy solar day and it stays at 3-4amps. Alternative would be to buy the new fob that they have to set it without having to discharge and unplug.

[xrated]

I went 11 days without shore, solar, generator being able to get SOC above 71% after an evening discharge to 11.7V but a SOC of 43% - still trying to figure that out. 40 minute diagnostic phone call with Progressive Dynamics - disconnect shore and solar and run the batteries down below 12.8V by turning on the fans and/or furnace. Then turn off fans and turn shore power back on (I did that at the breakers inside). Seems the PD 9160ALV can get fooled with a heavy solar day and it stays at 3-4amps. Alternative would be to buy the new fob that they have to set it without having to discharge and unplug.

Something was definitely wrong there. A 11.7V battery would be somewhat below or less than 10% SOC. A 40% SOC would be roughly in the 13.0 to 13.1V.....so yes, something was wrong with those numbers.

[deeuubee]

I went 11 days without shore, solar, generator being able to get SOC above 71% after an evening discharge to 11.7V but a SOC of 43% - still trying to figure that out. 40 minute diagnostic phone call with Progressive Dynamics - disconnect shore and solar and run the batteries down below 12.8V by turning on the fans and/or furnace. Then turn off fans and turn shore power back on (I did that at the breakers inside). Seems the PD 9160ALV can get fooled with a heavy solar day and it stays at 3-4amps. Alternative would be to buy the new fob that they have to set it without having to discharge and unplug.

Something is off with whatever is reading your numbers.
Even at 28% I'm still at 13.1V. I've never been below 13V LOL. (this is on my battery monitor gauge)

My PD 9160ALV is not hooked up all the time.
When I need to charge, I run the genny or plug in to shore power for a few hours.
It starts at 59ish amps, and always charges to 100% then I unplug it.
I'm not an AC guy, so no inverter yet. I can go dry camping 7-10 days without recharging the battery.
Depending on how much Netflix we watch.

[Butcher]

I do know I have all the parts to build my 302ah battery. I do not have time to build it now, but I will in a few weeks. I will initially charge the battery using my original WFCO converter. I will see how much this battery will charge. I will post my results. Pictures included. I will be on the 53% band wagon or not.

[xrated]

I do know I have all the parts to build my 302ah battery. I do not have time to build it now, but I will in a few weeks. I will initially charge the battery using my original WFCO converter. I will see how much this battery will charge. I will post my results. Pictures included. I will be on the 53% band wagon or not.

If you are building a LFP battery from four 3.2V cells, the very first thing you need to do is a top balance....no matter how close the individual cells voltage read is when you test them. Without a proper top balance, there is a very good likelyhood that the BMS will detect a cell over voltage and take the charging off line. All the BMS needs to see is one of the cells at greater than the setpoint of the BMS....which is normally set to something very close to 3.65V per cell. Make sure that your settings are NOT over the 3.65V per cell. A proper top balance is probably the single most important step in the battery build process.

I built mine back in the springtime, and right now (I checked them two days ago) and my four cells are within 2 millivolts of each other.... .002V. You just don't get it much closes than that.

[Butcher]

Yes, I am aware of the balancing that should be done before you properly put the battery in service. I have had great luck on the two batteries I have in service now. It took about 3 weeks to top balance my batteries to 3.65v with my small power supply. I really could care less about the time, I had a lot of irons in the fire.

What I want to prove to myself is, Is it true that the standard converter will only charge a lithium battery to 53% or will it go to a higher SOC like I suspect it would?

If indeed it does only get to 53%, then I doubt if any of the cells would top out and stop the charging process but I will of course watch that. I will post my results and let people take that it for what it's worth.

If none of the test results are accurate, I will start with a properly balanced battery, and post my results. Test results are only as good as the test itself. That is why I pointed out the voltage drop. If the drop is that bad, then that should be addressed before condemning the standard converter.